Creepy shit. Seems the kids are brainwashed, and given no choice. You either fight, or we kill you. ISIS hates us, because we kill them. We kill them, because they are a threat to our way of life, and they don't share the same ideologies as us. It will be a never ending cycle. We kill them, they hate us for it, and recruit more children. They seem to be growing in strength, numbers, and arms. However, they have no abundance of food or water, and they have no Navy. They currently are not a global threat, but they will always be a global nuisance.
What worries me the most is that they've become very organized, very quickly. All it would take is for them to get major financial backing, and then there might be a true threat.